I love those spawn dragon toys, they are such a perfect scale for hammer. I like the idea of converting one into a Coatl and you have a great start going. I would mirror everyone's comments on the wing size, but I am also a little put off by the one giant tooth. Did you pick some reference from a real work animal photo for this?
Great work on the green stuff feathers btw, I know how much work goes into them, and your sculpt of them looks amazing.